In such a case we have to use secure aliases of some non-secure
registers.

This behaviour is controlled via a flag in smmu->bugs. It is set
based on DT information when probing an SMMU device.

Signed-off-by: Andreas Herrmann <[email protected]>
---
 drivers/iommu/arm-smmu.c |   33 ++++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index b632bcd..46f2b78 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -60,6 +60,15 @@
 #define ARM_SMMU_GR0(smmu)             ((smmu)->base)
 #define ARM_SMMU_GR1(smmu)             ((smmu)->base + (smmu)->pagesize)
 
+/*
+ * SMMU global address space with conditional offset to access secure aliases 
of
+ * non-secure registers (e.g. nsCR0: 0x400, nsGFSR: 0x448, nsGFSYNR0: 0x450)
+ */
+#define ARM_SMMU_GR0_NS(smmu)                                          \
+       ((smmu)->base +                                                 \
+               ((smmu->bugs & ARM_SMMU_BUG_SECURE_CFG_ACCESS) ? 0x400 : 0))
+
+
 /* Page table bits */
 #define ARM_SMMU_PTE_PAGE              (((pteval_t)3) << 0)
 #define ARM_SMMU_PTE_CONT              (((pteval_t)1) << 52)
@@ -348,6 +357,8 @@ struct arm_smmu_device {
 #define ARM_SMMU_FEAT_TRANS_S2         (1 << 3)
 #define ARM_SMMU_FEAT_TRANS_NESTED     (1 << 4)
        u32                             features;
+#define ARM_SMMU_BUG_SECURE_CFG_ACCESS (1 << 0)
+       u32                             bugs;
        int                             version;
 
        u32                             num_context_banks;
@@ -611,16 +622,16 @@ static irqreturn_t arm_smmu_global_fault(int irq, void 
*dev)
 {
        u32 gfsr, gfsynr0, gfsynr1, gfsynr2;
        struct arm_smmu_device *smmu = dev;
-       void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
+       void __iomem *gr0_base = ARM_SMMU_GR0_NS(smmu);
 
        gfsr = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSR);
-       if (!gfsr)
-               return IRQ_NONE;
-
        gfsynr0 = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSYNR0);
        gfsynr1 = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSYNR1);
        gfsynr2 = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSYNR2);
 
+       if (!gfsr)
+               return IRQ_NONE;
+
        dev_err_ratelimited(smmu->dev,
                "Unexpected global fault, this could be serious\n");
        dev_err_ratelimited(smmu->dev,
@@ -1567,8 +1578,8 @@ static void arm_smmu_device_reset(struct arm_smmu_device 
*smmu)
        u32 reg;
 
        /* clear global FSR */
-       reg = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSR);
-       writel(reg, gr0_base + ARM_SMMU_GR0_sGFSR);
+       reg = readl_relaxed(ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sGFSR);
+       writel(reg, ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sGFSR);
 
        /* Mark all SMRn as invalid and all S2CRn as bypass */
        for (i = 0; i < smmu->num_mapping_groups; ++i) {
@@ -1588,7 +1599,7 @@ static void arm_smmu_device_reset(struct arm_smmu_device 
*smmu)
        writel_relaxed(0, gr0_base + ARM_SMMU_GR0_TLBIALLH);
        writel_relaxed(0, gr0_base + ARM_SMMU_GR0_TLBIALLNSNH);
 
-       reg = readl_relaxed(gr0_base + ARM_SMMU_GR0_sCR0);
+       reg = readl_relaxed(ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0);
 
        /* Enable fault reporting */
        reg |= (sCR0_GFRE | sCR0_GFIE | sCR0_GCFGFRE | sCR0_GCFGFIE);
@@ -1607,7 +1618,7 @@ static void arm_smmu_device_reset(struct arm_smmu_device 
*smmu)
 
        /* Push the button */
        arm_smmu_tlb_sync(smmu);
-       writel(reg, gr0_base + ARM_SMMU_GR0_sCR0);
+       writel(reg, ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0);
 }
 
 static int arm_smmu_id_size_to_bits(int size)
@@ -1881,6 +1892,9 @@ static int arm_smmu_device_dt_probe(struct 
platform_device *pdev)
                }
        }
 
+       if (of_property_read_bool(dev->of_node, 
"calxeda,smmu-secure-cfg-access"))
+               smmu->bugs |= ARM_SMMU_BUG_SECURE_CFG_ACCESS;
+
        INIT_LIST_HEAD(&smmu->list);
        spin_lock(&arm_smmu_devices_lock);
        list_add(&smmu->list, &arm_smmu_devices);
@@ -1943,7 +1957,8 @@ static int arm_smmu_device_remove(struct platform_device 
*pdev)
                free_irq(smmu->irqs[i], smmu);
 
        /* Turn the thing off */
-       writel(sCR0_CLIENTPD, ARM_SMMU_GR0(smmu) + ARM_SMMU_GR0_sCR0);
+       writel(sCR0_CLIENTPD,
+               ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0);
        return 0;
 }
 
-- 
1.7.9.5

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